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Dental Anatomy 10
Dental Anatomy Exam 10
Question | Answer |
---|---|
Deciduous mandibular central incisor erupts at what age | 6 months first tooth |
deciduous maxillary central incisor erupts at what age | 7 months |
deciduous mandibular lateral incisor erupts at what age | 7 months |
deciduous maxillary lateral incisor erupts at what age | 9 months |
deciduous mandibular canine erupts at what age | 16 months |
deciduous maxillary canine erupts at what age | 19 months |
deciduous mandibular first molar erupts at what age? | 12 months |
deciduous maxillary first molar erupts at what age? | 14 months |
deciduous mandibular second molar erupts at what age? | 20 months |
deciduous maxillary second molar erupts at what age? | 24 months |
permanent mandibular central incisor erupts at what age? | 6-7 years |
permanent maxillary central incisor erupts at what age? | 7-8 years |
permanent mandibular lateral incisors erupts at what age? | 7-8 years |
permanent maxillary lateral incisors erupts at what age? | 8-9 years |
permanent mandibular canine erupts at what age? | 9-10 years |
permanent maxillary canine erupts at what age? | 11-12 years |
permanent mandibular second premolar erupts at what age? | 11-12 years |
permanent maxillary second premolar erupts at what age? | 11-12 years |
permanent mandibular first molar erupts at what age? | 6-7 years |
permanent maxillary first molar erupts at what age? | 6-7 years |
permanent mandibular second molar erupts at what age? | 11-13 years |
permanent maxillary second molar erupts at what age? | 12-13 years |
permanent mandibular third molar erupts at what age? | 17-21 years |
permanent maxillary third molar erupts at what age? | 17-21 years |
what is dental lamina? | epithelial thickening in area where teeth will form |
what is the bud stage? | dental lamina differentiates and twenty tooth buds begin to appear on the dental lamina in the approximate location of the twenty primary teeth |
what is the cap stage? | bud is altered with basal invaginated and gives the appearance of a cap |
what is the bell stage? | basal area concavity deepens and the form of the tooth can be recognized dentinoenamel junction is definable and most of the crown's dentin and enamel is laid down |
when does bell stage end? | when CEJ is formed and root development begins |
what is Hertwig's sheath? | enamel organ where the root is formed |
how long does the development of the dental organ last? | 5 1/2 years |
what are the stages of the development of the dental organ? | Bud stage Cap stage Bell stage |
when do primary teeth begin to develop? | the first few months in utero |
when do succedaneous teeth begin to develop? | five months in utero to 10 months after birth |
when do permanent non succedaneous teeth begin to develop? | four months in utero to five years after birth |
what is eruption? | prior to complete calcification of its root the tooth pushes through the mucous membrane cover of the alveolar process and into the oral cavity |
what is eruption considered finished for a tooth? | when the tooth contacts opposing tooth |
what is active eruption? | tooth's entry into the oral cavity to its contact with an antagonist in the opposing arch |
what is passive eruption? | continuing process of adaptation of the tooth to changing incisal and occlusal relationships after active eruption has ended. due to attritional wear and changing locations of adjacent and opposing teeth CONTINUES THROUGHOUT LIFETIME OF THE TOOTH |
what is Nasmyth's membrane? | when the tooth erupts a keratinous membrane like enamel cuticle envelopes the anatomical crown which is then abraded away |
what is the sequence for primary teeth eruption? | mandibular centrals first at 6 months mandibular lateral incisors and then maxillary central incisors |
at approximately 2 years of age... | children have their maxillary second molars and thus has function of all the deciduous teeth |
when is root formation complete? | additional dentin deposition reduces the funnel shaped opening to a constricted foramen |
at age 3 root formation... | has ended for all deciduous teeth |
what is the time lag between eruption and root completion for the deciduous teeth? | 1 year |
what is the time late between eruption and root completion for the permanent teeth? | about 2 years |
where are the permanent incisor and canine buds found when developing? | just lingual to the roots of their deciduous predecessors |
where are the premolar buds located during eruption? | in the root furcation of the deciduous molars |
where are the permanent molars that are not succedaneous teeth buds develop? | dental lamina in the alveolar process distal to the deciduous dentition |
what ends the deciduous dentition stage and initiates the mixed dentition stage? | eruption of the mandibular first molar |
why are the mandibular first molars considered the cornerstones in the development of occlusion? | guide eruption of other permanent teeth if they are lost early it could cause tipping or crowding because of the loss of space |
what is the sequence for permanent eruption? | mandibular first molars at age 6 maxillary first molars |
when does mixed dentition start and end | starts: age 6 with the eruption of 1st molars ends: at age 12 with the exfoliation of the 2nd molars |
what is resorption? | root of deciduous tooth is melted away starts at the apex and moves towards the cervical line |
what are the thoughts on the reason for initiation of reposition? | pressure from the permanent tooth crown against the deciduous root osteoclastic activity |
what is exfoliation? | when the root structure of the deciduous tooth is almost entirely resorbed the remaining crown becomes some loosened that it is lost |
how does exfoliation occur? | symmetrically with the same teeth of the right and left sides being lost at about the same time mandibular teeth generally precede the same maxillary teeth |
what the exception to exfoliation? | second molars where all four are lost at the same time |
what is ankylosis? | root structure of the deciduous tooth becomes fused to the surrounding alveolar bone, any further eruption ceases and the tooth becomes fixed in position and resumption cannot progress naturally |
what teeth most often are ankylosed? | deciduous molars |
what is the etiology of a dental anomaly? | hereditary, congenital (at birth), developmental disturbances, metabolic disturbances |
what set of teeth are most likely to have anomalies? | permanent dentition |
what is anodontia? | literally means complete lack of teeth but the meaning has come to include any missing teeth even if it is only one teeth that are impacted are not considered missing |
what causes anodontia? | some type of disturbance during the initiation process of tooth development, most often a hereditary process |
what is hypodontia? | agenesis of one or more teeth |
what is total anodontia? | complete absence of teeth or large number of missing teeth sex linked genetic trait |
what is partial anodontia? | one or a few missing teeth results from hereditary factors found in 5% of individuals |
what are the most commonly missing permanent teeth? | maxillary and mandibular third molars maxillary lateral incisor mandibular second premolar rare in primary but involves mandibular centrals if it is found |
what are the most sound and stable teeth? | canines |
what are supernumerary teeth? | excessive number of teeth that do not resemble any normal tooth in size or shape result when extra tooth buds differentiate from the dental lamina and considered to be genetic can affect both primary and permanent dentition 1-2% of the population |
what are mesiodens? | supernumerary teeth between maxillary central incisors |
what are distodens? | supernumerary teeth between the third molar regions |
where are supernumerary teeth often found? | similar areas where anodontia occurs premolar, third molar, maxillary anterior areas |
abnormal size of teeth is a result of... | disturbance during the morphodifferentiation in the bell stage with a genetic etiology |
what is true macrodontia? | pituitary gigantism all the teeth are abnormally large |
what is false macrodontia | individual teeth are excessive in size most frequent are incisors, canines and mandibular third molars |
what is true microdontia? | pituitary dwarfs all the teeth are abnormally small |
what is false microdontia? | individual teeth most frequently maxillary laterals incisors, maxillary third molars |
what is taurodontism? | large pulp chamber, furcation in apical half of the root diagnosed by x-rays, most often because of hereditary |
what is dilaceration | distortion of the crown and the root occurs because of trauma or pressure |
what is flexion? | distortion of the root portion only occurs later on in development |
what is gemination? | incomplete splitting of a tooth germ has a single root and a common pulp cavity additional tooth in the dentition |
gemination is normally found on... | incisor |
twinning is what | identify a situation where gemination has been complete, resulting in two identical teeth and thus an additional tooth in the dentition |
what is fusion? | union of two tooth buds caused by hereditary or pressure normally has separate pulp chambers count one less tooth in dentition |
fusion is normally found on... | anterior teeth, most often deciduous teeth |
what is concrescence? | union of root structure of two or more teeth through the cementum only normally occurs following eruption and never involves enamel and dentin makes teeth hazardous to extract |
what is a segmented root? | disturbance dring root development and results in two separated root segments break in Hertwig's sheath |
what are dwarfed roots? | normal sized crowns have abnormally short roots caused by heredity risk of early loss due to short root |
what is hypercementosis? | excessive cementum formation at apex usually found on permanent molars |
what is the etiology of hypercementosis | chronic inflammation of pulp trauma local or systemic metabolic disturbance |
accessory cusps most likely found on | 3rd molars and maxillary incisors (talon cusps) |
accessory roots caused by | trauma, pressure or metabolic reasons |
missing cusps usually seen on | lingual on mandibular 1 premolar distolingual of maxillary molars distal of mandibular molars |
what are enamelomas? | enamel pearls, small spherical nodules of enamel attached to root surfaces normal found on fucation areas of molars |
what causes enamelomas? | disturbance in hertwig's sheath |
what are hutchinson's teeth? | due to prenatal syphilis and caused by disturbance in calcification screwdriver shape to incisors, mulberry appearance on 1st molars |
where are dens in dente normally found? | maxillary lateral defect in lingual surface |
what are odontomas? | benign tumor developmental disturbance of dental lamina, trauma or infection |
what is a complex odontoma? | one mass of calcified dental tissue |
what is compound odontoma? | arranged in the shape of a recognizable tooth form |
what is enamel dysplasia? | characterized by bands, ridges or potted areas of discolored enamel happens during enamel matrix formation |
what causes enamel dysplasia? | local, systemic and hereditary factors |
when does enamel hypo calcification happen? | during matrix maturation |
what is amelogenesis imperfecta? | complete absence of enamel to enamel that was deposited but failed to fully mature heredity, rampant carries risk or excessive attrition risk |
what is focal hypo maturation? | chalky, white opaque area that is circular and defined susceptible to caries and often found on anterior teeth |
what is dentinal dysplasia? | disturbance of dentin matrix formation and calcification dentin involved, not enamel |
primary sequence of eruption? | mandibular centrals mandibular laterals maxillary centrals and laterals mand/max 1st molars mand/max canines mand/ max 2nd molars |